Ecotourists increase anxiety and stress in macaques

Wildlife tourism is already thought to stress many species. To study its effect on Barbary macaquesMacaca sylvanus) in the Ifrane National Park of the Moroccan Atlas mountains, Laëtitia Maréchal and Stuart Semple

of the University of Roehampton, London, recorded levels of glucocorticoid hormones - an indicator of physiological stress - in the monkeys' faeces. They also monitored rates of self-scratching, which relates to anxiety.

The researchers found that the greater the number of tourists present and the more they interacted with the monkeys - even in seemingly innocuous ways such as taking photos or giving them food - the stronger the likelihood that the monkeys would become anxious. Any show of aggression from tourists pushed the animals into full-blown physiological stress.

"That's particularly worrying in situations where people and monkeys are in very close proximity," says Semple. "We can pass pathogens to monkeys, and high stress levels can make it more difficult to fight them off." Such studies are vital to help establish wildlife tourism guidelines, he says.